668146291 has 16 divisors (see below), whose sum is σ = 729273888. Its totient is φ = 609638400.

The previous prime is 668146253. The next prime is 668146309. The reversal of 668146291 is 192641866.

It is a 11-Lehmer number, since φ(668146291) divides (668146291-1)¹¹.

It is a cyclic number.

It is not a de Polignac number, because 668146291 - 2⁷ = 668146163 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668146091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110671 + ... + 116551.

It is an arithmetic number, because the mean of its divisors is an integer number (45579618).

Almost surely, 2^668146291 is an apocalyptic number.

668146291 is a deficient number, since it is larger than the sum of its proper divisors (61127597).

668146291 is a wasteful number, since it uses less digits than its factorization.

668146291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6102.

The product of its digits is 124416, while the sum is 43.

The square root of 668146291 is about 25848.5258960738. The cubic root of 668146291 is about 874.2262726515.

The spelling of 668146291 in words is "six hundred sixty-eight million, one hundred forty-six thousand, two hundred ninety-one".